Dolls are toys made to entertain people, especially children. Dolls which are made to impersonate a human or a pet may provide certain degrees of satisfaction for virtual companionship. Sophisticated dolls may be made with materials and more details to closely resemble the real object may provide a sense of warmth and comfort when being handled, nevertheless, a lack of ability to interact and respond back to human still cannot fulfill a sense of reality.
Technology provides limited doll interactions to respond to human's touch. For example, some dolls are made to include an acoustical generator, which produces sounds or speech when being pressed. However, the sound and speech patterns are quite routine and repetitive; therefore the interactive experience may be monotonous and lack reality perceptions.